Phnom Penh , Cambodia -LRB- CNN -RRB- -- Late one night , after dark , we met up with Don Brewster -- head of Agape International Missions , an NGO fighting child prostitution -- to go behind the scenes at Cambodia 's KTVs : karaoke clubs that are fronts for brothels .

I threw on some jeans and tried to look like a tourist who was up for a kinky kind of tour , with my ersatz `` boyfriend '' -- our cameraman , Scott .

Don drove us first to an out of the way small side street , where there were tiny KTVs operating out in the open like cheap brothels . Girls sat on plastic chairs lining the entrance , all painted up and wearing short skirts , high heels and fake smiles . We walked past a few , stopping to talk for a little while . The girls would stand up , becoming energized and engaged . We crossed the street and approached another one , as if we were sampling the wares at each one .

We walk into a KTV ; Scott and Don lead the way into the karaoke rooms . I become less nervous as we walk to the back where an overweight young woman frantically sweeps the kitchen floor , and we are pointed up some cement and metal stairs . We pass hallways full of closed doors , in which I can only imagine the sex acts occur .

We are brought into a low ceilinged , dank room with some disgusting couches and a video screen on one wall . I am overwhelmed with the saturated smell of air freshener that apparently has gone off like an insect fogger in this room -- to cover what odor , who knows . I nearly gag and we beat a quick path out of there . We hop back into the car and head off .

Next stop : a famous 5-storied fortress of a KTV with armed guards outside . Don says if we take the elevator up from the basement , we can skip the bar and go straight to the `` massage '' floor .

On the fifth floor we are immediately led to a giant windowed `` fishbowl '' where at least 20 girls sit on bleacher to be observed and picked . Scott walks in front of the pane ; they respond to his macho energy , rising and preening .

I have my iPhone in hand and itching to take a picture when suddenly things go horribly sideways : A white-clad girl in the bowl suddenly jumps up and starts screaming `` She take a picture !! '' She runs into the lobby and a grim-faced Mama-san bustles up to us . The girl crowds us and accuses me ; more people start to gather . My friends advise me to erase the picture -- but I have n't taken any ! I try and stand my ground and keep saying , `` I did n't take a picture . '' But I am becoming very nervous and the situation is getting ugly .

We hustle back onto the elevator . We were lucky to get out of there without running into the security guys , because there could have been real trouble . But their behavior absolutely cemented the fact that something illegal , beyond legal-aged prostitution is going on there . They were acting like they had far too much to lose .

We head to another KTV , this one still upscale but less fortress-like than the last . Paintings of the cosmos line the ceiling in the lobby . We were ushered in and led us upstairs to karaoke room where hostesses in satin , beaded formal dresses greet us . The large and comfortable room had a giant screen on one wall and couches lining the other three walls . Colored lights pulse and change on the walls .

An older woman walked in five girls dressed in fairly classy though sexy business suits , for us to take our pick of whom we would like to stay with us . Scott , fully playing the part , roars out in his New Zealand accent , `` You have anything younger , fresher ?! '' The girls scurry out in a hurry .

Then more girls enter . These definitely seem younger . They are also more provocatively dressed ; they are wearing very short little black dresses . Don picks one , and so does Scott and the two join us ; the karaoke starts in earnest . I must sing with gusto to justify my presence , otherwise what is this white lady doing here ?

We sit there and begin to get their life stories . The young girl sitting next to me , the one Scott chose , is extremely pretty . It is impossible to tell how old she is -- she claims to be 21 , I would believe it if she was 14 . She says she does n't come from Phnom Penh , and she is working here because her family is very poor and needs the money . Her family does n't know what kind of work she is doing , she said . If they find out , they will be angry with her . She has a very pretty smile , but there are moments when I watch her where the smile disappears , and she looks very sad .

She chooses to sing a song from the Karaoke catalog , a popular dance hit in Khmer , which has a video of a singer performing in front of what looks to be an American style high school dance , again like a prom . I am told the song is called `` Only One Virginity '' -LRB- ! -RRB- and it talks about how a girl is like a flower , and only has the one time where she has most value .

Our young acquaintance sings her heart out , very intently performing if not always tunefully . Afterwards she tells me that she very specifically picked this one out , and that she wishes that she will meet a man that will go to her parents and ask for her hand , respect her . I try to get her to talk about what men expect from her here , but it does n't go very far .

I see that Don has been very busy with the girl he invited to stay , showing her a video on his iPhone in which a girl from his center talks about how she was able to leave a KTV and now has a job that she is excited about and is much happier . She was very intrigued by the video and she gave him her cellphone number so the girl from the video could call her and follow up .

I passed his iPhone to our young companion . Thankfully , the hostesses did not seem to mind or care that we were doing this ; the whole room was on security cameras poised in the corners but no one came in and stopped us . She watched and listened to the video very intently . Afterwards she said she liked it .

`` I know it is hard to trust us , strangers , '' I told her . `` But I am a mom -LRB- and I showed her pictures of my four happy children and me hugging my two daughters -RRB- and I would n't want my kids in a situation like this . ''

She did n't give her number , but we told her it was okay , Don 's outreach person would call her friend and we gave her Don 's card . I impressed on her that this was opportunity knocking on her door , and she should answer it : this was her chance for a happier life .

We hugged goodbye , and went back to the cars . I had no idea that I was going to be involved in trying to recruit girls to leave the KTV life and receive the services of Don 's NGO . What a night .

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Mira Sorvino takes a behind the scenes look at Cambodia 's child sex trade

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Karaoke bars are often fronts for prostitution in Phnom Penh , the country 's capital

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When a club hostess is asked to bring in younger girls , she obliges

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Girls are shown messages from others who escaped life from these covert brothels